LONDONBERRY, N.H. — On the rise in a tightening race, Marco Rubio shouldered intensifying attacks Friday from moderate-leaning Republicans who fear a strong Rubio showing in Tuesday’s New Hampshire primary could spell the end for their frazzled presidential campaigns.

Jeb Bush and Chris Christie both accused Rubio of a lackluster set of accomplishments. Bush, campaigning with his mother, former first lady Barbara Bush, summed up the Florida senator’s achievements in one word: “Nothing.”

On the Democratic side, the gloves were off in a campaign that had shown more signs of comity than rancor – until now. A day after jousting in a feisty debate, Hillary Clinton struggled to defend herself against Bernie Sanders’ insinuations that she’s beholden to Wall Street, while Sanders faced fresh doubts about his experience on foreign policy.

As candidates crisscrossed the state, a burst of soggy snow became the latest obstacle to winning support among undecided voters. The winter surprise sidelined Donald Trump and Sanders, who canceled afternoon events as campaigns sent plucky volunteers trudging through the slush to knock on doors.

Storm notwithstanding, the all-out push for votes illustrated the growing stakes for Tuesday’s vote. New polls showed Rubio on the rise both in New Hampshire and nationally, raising his hopes that a second-place finish Tuesday will spur Republican Party leaders to unite behind him in a bid to defeat the two polarizing front-runners: Trump and Texas Sen. Ted Cruz.

“Marco is a talented politician,” Bush said on MSNBC. “He’s a great guy, but he’s not a leader.”

His campaign released a new TV ad showing former Sen. Rick Santorum, who has endorsed Rubio, stumbling in an interview to name one Rubio accomplishment.

Rubio did pick up another endorsement from a fallen rival – former Louisiana Gov. Bobby Jindal, who dropped out of the race in November.

Cruz, the victor in last week’s Iowa caucuses, was struggling to put complaints about his campaign’s tactics in the rearview mirror, as new evidence emerged of what challenger Ben Carson has dubbed “dirty tricks.” Carson told a Fox News podcast that Cruz’s lackadaisical defense brought to mind Clinton’s response to the attacks in Benghazi, Libya.

Fueling the dust-up were rumors spread by Cruz’s campaign hours before the Iowa caucuses about Carson dropping out of the race. Trump has also cried foul, arguing Cruz “stole” the election by peeling off Carson supporters to surge past Trump.